The invention relates to a process for the production of shaped articles using splitting techniques, known per se, in particular to the production of concentric supporting or bearing surfaces as components of articles. The supporting or bearing surfaces are made by splitting the edge portions of a plate-like intermediate product and then forming them to the desired configuration of the supporting or bearing surface without removal of metal, after which the rest of the plate is formed by flanging and/or division to a support means for the mounting, if desired so as to be movable, of the supporting or bearing surface in the article.
Splitting techniques in which an edge portion of a plate-like article is split and then shaped without removal of metal are, for example, disclosed in U.S. Pat. Nos. 3,540,395 and 3,758,930. The present invention is based on the appreciation that by appropriate adaptation of the rest of the plate-like intermediate product the construction of various articles in which supporting or bearing surfaces are present can be considerably simplified, both because the number of component parts of the article can be reduced, and because complicated centering procedures are eliminated.
Thus, using the process of the invention it is possible to make a rolling bearing, in particular for a castor with an upper fixing plate and a swivelling fork which carries the wheel. In accordance with the invention, the outer race of the bearing is produced by splitting the edge of a central aperture in a plate and then calibrating to the dimensions of the rolling elements applied in the bearing, the remainder of the plate being formed by forcing to a dish with an edge portion located in a plane surface, the said dish being closable by a flat cover having features concerning mounting and lubrication. The dish forms a space for the accommodation of a lubricating grease chamber, and, in a further embodiment of the invention, the inner bearing race is produced by forcing the upper part of the material of the swivelling fork, so that apart from one or two covers and plugs, which may be made from plastics, the castor has only two elements, namely the outer bearing race with top plate and the inner bearing race produced in one piece with the fork.
Another suitable application of the process of the invention is the production of the housing of an "Y-bearing", which housing has a bearing seat for the outer race of the Y-bearing. In accordance with the invention, the bearing seat is made by splitting the edge portion of an aperture in a plate, the said edge portion then being formed without removal of metal to a bearing seat of the desired concave configuration. The bearing housing of the invention is light and strong, since at the position of the maximum bearing load the bearing seat is fully supported by the completely undivided plate material. In a further embodiment of the invention, the plate material may be split rather more deeply than is strictly necessary for the formation of the bearing seat, such that during the subsequent forming without removal of metal an annular groove is left in the middle of the bearing seat which can function as a circumferential lubrication channel.